The aim of the project is to investigate a new method to test epoxy resin coatings in steel tanks for pinholes. The method should be scientifically established and included as a further test method in the DVGW worksheet W 628 “Internal coating and lining of steel tanks in waterworks”.
In the DVGW-funded research project, TZW investigated the application of an alternative/supplementary test method to accept epoxy resin coatings in coated steel containers in waterworks by means of laboratory and field trials. Defects are indicated by rust streaks that form once the tank is filled with water and left for several days. The aim of the research project was to develop the water test in this context to provide a simple, quick, reliable and cost-effective test method to detect pinholes, cracks and processing errors in the surface coating of steel tanks immediately after construction. The main issue here was to investigate the efficiency of the water test taking into account the operating conditions and application limits. Relevant laboratory and field trials were conducted. These showed that when testing the finished coating, it was adequate to fill the tank with water available on site as test water, and to leave it to stand under operating pressure for seven days. This period is sufficient for clearly visible rust streaks to form in the defective areas. Further requirements, for example, on the test water composition are not needed.
As a result of the findings obtained in the research project, the water test has since been included in the DVGW worksheet W 628 in the form of a supplement, as an additional method to reliably determine defective areas in epoxy resin-coated steel tanks in waterworks.
Publications:
Turkovic, R.; Feinauer, F.: Standardisierung eines Testverfahrens zur bauseitigen Qualitätsbeurteilung der Beschichtungsausführung von Epoxidharz-beschichteten Trinkwasser-Stahlbehältern [Standardisation of a test method for the on-site quality assessment of the coating design of epoxy resin-coated steel tanks for drinking water]. DVGW energie|wasser-praxis 02/2018, 22-29 (2018)
